Numerous disciplines in rehabilitation medicine and related fields have benefited from the ability to record the electrical activity from a muscle contraction. A number of technological advancements have evolved to improve the fidelity of these surface electromyographic (SEMG) signals. However, current hardware limitations preclude the use of the technique for vigorous activities because of motion and sweat artifact. The proposed program will address these problems by focusing on the electrode-skin interface. The primary aims of Phase I are: 1. To evaluate the ability of the skin-electrode interface to mechanically and electrically couple the SEMG electrode to the skin maintaining its integrity during long-term strenuous activities. 2. To implement a standardized test procedure to evaluate the ability of the electrode/interface to provide mechanical and electrical stability to the SEMG electrode during controlled increments of sweat accumulation on the skin. The commercial development of an advanced SEMG system will be continued during Phase II by: 1) finalizing the evaluation of the SEMG interface under conditions of rapid loading, stretching/shortening of skin; 2) creating a new SEMG electrode for use with an interface to provide a generic detection system; 3) developing modules that are attachable to the generic prototype for applications in which severe conditions of rapid loading, stretching/shortening of skin and sweat are encountered. PROPOSED COMMERCIAL APPLICATION: Successful completion of the proposed project in conjunction with our previous work will lead to the development of a new data acquisition system for monitoring electromyographic signals from skeletal muscles. The commercialization of a new generation of surface EMG sensors for effective, non-invasive diagnosis, prevention, and treatment of musculoskeletal disorders is foreseen. The new instrumentation will expand current use of electromyography into a wider variety of applications in rehabilitation medicine, sports, and ergonomics.